Work supports for machine tools



De@ HQ, 3935. T B, BUELL v 2,923,859

WORK SUPPORTS FOR MACHINE TOOLS f Filed NOV. 22, 1955 n E N@ `1 i g Si? $3 i @'n Y N i @E Fatented Dec. 10, 1935 WORK SUPPORTS FOR MACHINE TOOLS Timothy B. Buell, Rockford, Ill., assignor to Sandstrand Machine Tool Co., Rockford, Ill., a corporation of Illinois Application November 22, 1933, Serial No. 699,210

4. Claims. (Cl. .9o-59) This invention relates generally to Work supports for milling machines and other machine tools, and more particularly to a work support embodying a new and improved iixture clamping mechanism.

In mounting work pieces on the Work supports or tables of milling and other types of machines, it is generally customary to mount the piece in a fixture or work holder rather than to clamp it directly to the table by means of bolts secured in inverted T-slots. This practice is customary particularly when the work pieces are relatively small or when they are of such shapes that x` tures with special clamping jaws or means are l5 necessary for the purpose of securely holding the Work in its proper position during the cutting operation. Such fixtures are often provided with quickly operable clamping devices so as to facilitate the removal of finished work pieces and the mounting of work blanks.

It has been found that there are numerous instances in which it is desirable and even necessary to change the Work holder xture itself quite frequently. Generally the xtures are secured to the table by means of bolts in inverted T-slots or some other rather permanent manner, so that the removal of one iixture and the substitution oi another requires an appreiciable amount of time. It is the general object of this invention to provide a work supporting structure embodying a table or support and a detachable work iixture or holder, together with new and improved means for securing the Work iixture or holder detachably to the table in such a maniler that the parts are rigidly attached during the cutting operation, but may bequickly separated and the iixture removed from the table for the purpose of substituting another fixture which may be required for holding other types or sizes of work pieces.

Another object is to provide a novelxture clamping mechanism which can readily be installed on existing work tables and fixtures with a minimum amount of machining.

Another object is to provide a work supporting means embodying a table and axture and a novel xture clamping mechanism together with means for properly positioning or alining the fixture on the table.

Further objects and advantages Will become readily apparent from the following detailed de scription taken in connection with the accompanying drawing, in which:

55 Fig. 1 is a longitudinal central section through a milling machine table, illustrating a preferred form of the invention.

Fig. 2 is a view looking at the left hand end of Fig. 1, and partly in section, along the line 2 2 of Fig. 1. 5

Fig. 3 is a fragmentary section along the line 3 3 of Fig. 1.

Fig. 4 is a View looking at the bottom of the work fixture.

Although I have illustrated in the drawing l0 and shall herein describe in detail a prefererd form of the invention as embodied in a work support for a milling machine, it is with the understanding that I do not thereby intend to limit the invention to the specific form or arrangement l5 shown, but aim to cover all modications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

In the drawing, 5 represents the table of a 20 milling machine slidably mounted on a bed E and guided thereon along Ways 1. This table is provided with the usual longitudinally extending inverted T-slots 8 for the reception of clamping bolts for the work or work fixtures. 25

A work iixture is herein illustrated at 9 and since the specific work clamping means on the fixture may be of any preferred or desired form they are indicated generally at I0. The iixture is herein shown in the form of a somewhat rec- 30 tangular metal block and is preferably provided with positioning means in the shape of keys Il, i2, i3 and I4 which are arranged to engage in slots in the surface of the table for locating the fixture on the table. Thus the keys Il and i2 35 engage in the central T-slot 3 and the keys I3 and lll engage in transversely extending slots or recesses I5 cut across the central portion of the top of the table. The xture has a vertically positioned opening Il across which a pin I8 ex- 40 tends. Thisv pin forms a part of the means for clamping the fixture to the table and to that end is axially removable and is arranged to be engaged by means of a hook-like member I9 which has a cylindrical portion 20 slidable vertically in 45 a bushing 2! mounted in a recess 22 in the table. The bushing 2l is preferably provided with a reduced portion 23 so as to form a shoulder 24 engaging an abutment 25 on the table so as to prevent movement of the bushing upwardly in the table during the clamping operation.

As illustrated herein the means for raising and lowering the clamping member i9 is shown as comprising a bar or rod 2l positioned in a longitudinally extending bore 28 in the table 5 and 55 extending through openings 29 and 30 in the bushing ZI and the cylindrical portion 20 of the clamping member respectively. The rod 21 is provided with an inclined or cam surface 3| arranged to cooperate with a corresponding cam surface 32 on the clamping member I9,'so that when the rod 21 is moved toward the right (Fig 1) the clamping member I9 Vwill be drawn downwardly to secure the fixture 9 rigidly to the table whereas when the rod 21 is moved toward the left the clamping member will be released. With the clamping member released the pin I8 may be withdrawn axially, thereby freeing the fixture for removal by simply lifting the same vertically oi of the table. In the preferred form of the invention the rod 21 is arranged to be actuated by means of a screw device 35 which is threaded into the outer end of the bore 28vin the table 5, and is provided with a squared end 36 for the reception of a suitable tool. This screw device has a reduced portion 31 extending into a socket 38 in the adjacent end of the rod 21, and has a peripheral groove 39. A pair of pins 4D, extending in laterally spaced relation through the rod 21, engage in the groove 39 so that when the screw device 35 is turned the rod 21 will be moved longitudinally without being rotated. Prefer-V ably, as illustrated in Fig. 1, the end of the rod 21 abuts the large portion of the screw device 35 during the clamping operation. Thus the pin connection need only be suiciently strong to withdraw the rod 21 when the clamping member is loosened.

It will be readily apparent thatrthe invention not only provides a readily operable mechanism for quickly clamping a work fixture to a table, but also provides means for properly positioning and alining the fixture on the table. Thus 'xtures having differently shaped Vor constructed clamping means may be provided with similarly positioned keys I I, I2, I3 and I4, and pins I8 so as to permit one xture to be readily substituted for another. 'I'he clamping mechanism may be readily applied to the table of an existing machine merely by drilling the necessary vertical holes for the bushingZI, and the longitudinally extending bore 23 for the operating rod 21. Since the lugs I I and I2 may t into the central T-slot ordinarily found on a table, it is only necessary to add the cross slots. By positioning the pin I8 in the forward portion of the xture or'immediately adjacent the Work holding portion thereof a rigid connection between the xture and table is secured immediately adjacent the Work.

I claim as my invention:

1. Work supporting means for a machine comprising, in combination, a table having respectively perpendicular recesses in its upper surface, a removable work fixture adapted to be mounted on the table having locating keys adapted to engage in said recesses for definitely positioning said fixture both laterally and longitudinally of the table, and means for securing said fixture Vto the table comprising a vertically slidable clamping member inthe table having means adapted to engage said work xture, cam means interposed between said table and said clamping member for actuating the latter, and screw means 5 for actuating said cam means to loosen or tighten said clamping member.

2. Work supporting means for a machine comprising, in combination, a table, a work xture adapted to be removably mounted on the table, 10

Vsaidriixture having a central recess, and means for securing said xture to the table for vertical removal comprising a pin extending transversely across the recess in said fixture and axially removable, a vertically slidable clamping member 15 in the table having a portion projecting above the surface of the table and received in the recess in said xture when the same is placed on the table, said portion having an aperture through which said pin projects, and cam means for 20 drawing said clamping member downwardly thereby to secure said pin against axial movement and said xture against removal.

3. Work supporting means for a machine comprising, in combination, a table having respec- 25 tively perpendicular recesses in its upper surface,

a removable work xture adapted to be mounted on the table having locating keys adapted to engage in said recesses for definitely positioning said fixture both laterally and longitudinally of 30 the table, said iixture also having a central recess, a vertically slidable clamping member in the table having a portion projecting above the upper surface of the table and received in the recess in said xture when the same is placed 35 on the table, said clamping member having an aperture in the portion projecting into said xture and a cam slot in its other end, a pin projecting transversely of the recess of said fixture and through the aperture in said clamping mem- 0 ber, said pin being axially removable when the clamping member is released to permit vertical removal of said xture, and cam means engaging said cam slot and operable to draw said member downwardly to secure said pin and said xture 45 against removal.

4. Work supporting means for a machine comprising, in combination, a table having respectively perpendicular recesses in its upper surface,

a removable work xture adapted to be mounted 50 on the table having locating keys adapted to engage in said recesses for denitcly positioning said xture both laterally and longitudinally of the table, a vertically slidable clamping member in the table projecting above the table for engage- 55 ment with said xture, cam means for actuating said clamping member, and means carried by said xture engaged by said clamping member when in clamping position to secure said xture and wholly disengageable from said member when in released position to permit vertical removal of said fixture.

` TIMOTHY B. BUELL. 

